Carbon black is commonly produced by pyrolytic decomposition of hydrocarbons. The heat for this decomposition is usually provided by the combustion of fuel gas and air. The hydrocarbon feed used can be a gaseous hydrocarbon or a normally liquid hydrocarbon.
It is known in the art that a furnace-type carbon black, which can be used as an important ingredient in a rubber, both for tire tread and tire carcass, can be produced by contacting the hydrocarbon with hot combustion gases in a tubular or essentially cylindrical reactor. Such a reactor generally consists of a steel shell and a refractory lining made from, e.g., ceramic material.
Several parameters influence the properties of carbon black. Flow velocities, air to hydrocarbon ratio, gas to hydrocarbon ratio, reactor shape, etc., are important parameters. The change of any one of these parameters changes the properties of carbon black considerably. In order to utilize this situation, it has been proposed to make the axial position of the oil nozzle adjustable. Another proposal in the art is to make the size of a combustion chamber adjustable and to make the speed of hot combustion gases introduced into a reactor adjustable. By these various adjustments, the properties of carbon black can be controlled.
It would be desirable to have a carbon black reactor available in which the axial flame length of burners producing hot combustion gases can be adjusted. This would be particularly advantageous if it could be done without changing the quantity or composition of hot combustion gases, since these parameters also influence the properties of the carbon black produced.